Some of the more recent napkins designs, in order to address the art-recognized lateral leakage problem, have included side panels, flaps or wings that extend laterally from the longitudinal sides of a central absorbent. See U.S. Pat. Nos. 4,608,047; 4,285,343; and 4,589,876 which are hereby incorporated by reference. These products are designed to protect the undergarments of their users by wrapping around the crotch portion of an undergarment, such as a panty, in order to prevent leakage onto the undergarment.
The flaps and central absorbents of these napkins usually have body fluid impervious surfaces that face the surface of the undergarment. Usually, adhesive is disposed on their body fluid impervious surfaces as a means for attaching the product to a user's undergarment. These adhesive elements are often covered with separate release strips for packaging and shipping which act to protect the adhesive from dirt and unintended adhesion during manufacture, packaging and storage. These strips can be removed by the user immediately prior to application of the product. See U.S. Pat. Nos. 4,285,343 and 4,589,876. Multiple adhesive elements and release strips, however, can present the user with a cumbersome process when preparing the product for use. The user often has to remove three release strips located under both side panels and the central absorbent, while simultaneously attempting to prevent the flaps from inadvertently adhering to one another or to another part of the product. Should such adherence take place, the product would be rendered useless. Moreover, the additional adhesive system on the flaps can produce additional fouling of the undergarment material due to adhesive transfer. Even when the problem of undesired adhesion is avoided, the user is presented with the task of disposing of three release strips.
One proposed solution to some of these problems has been to provide packaged winged napkins with adhesive located on an undergarment-facing side of their central absorbent element and on an undergarment-facing side of one or both of folded flaps, with a protective release strip located between the adhesive on the flaps and that of the central absorbent. See U.S. Pat. No. 4,701,178, which is herein incorporated by reference. While such products conserve release strip material and avoid inadvertent adhesion of the flap adhesive, they generally require that the release strip be treated so that both sides of the strip have releasable coatings on them.
Furthermore, napkins that provide release paper between their flaps and central absorbent can be damaged during preparation for use. A user may deform the product when removing the release strip, as the release strip would tend to pull at the junction between the flaps and the central absorbent. The potential for damaging the napkin is even greater when the flaps overlap and one flap bears adhesive. In such designs, the release strip would exert a tensile force upon the flaps prior to releasing the adhesive between them. This force could damage one or both flaps due to stretching or tearing, prior to the disengagement of the flap-to-flap adhesive element.
Accordingly, a need exists for a sanitary napkin having side protecting flaps and can be manufactured using a single release paper strip. There is also a need for a winged sanitary napkin which can applied without transferring adhesive to a user's undergarment.
It is therefore an object of this invention to provide a winged sanitary napkin that can be manufactured with a single release paper strip.
It is another object of this invention to provide a winged sanitary napkin that is garment-protecting, and can be prepared for application without a risk of damaging its flaps.
With these and other objects in view which will become apparent hereinafter, this invention resides in the novel construction, combination, arrangement of parts and methods substantially as hereinafter described and more particularly defined in the attached claims.